Calculating device in the form of a slide rule



P. LOTZBEYER CALCULATING DEVICE IN THE FORM OF A SLIDE RULE r1154 June27. 1924 a sgmzkshm. 1

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H., 1 .9 a n M V I 9 7w Sept; 14, 1929.

Sept. 14 1926. 1,599,904

P. LOTZBEYER CALCULATING DEVICE IN THE FORM OF A SLIDE RULE F'ilad June27, 1924 2 Sheets-She et 2 Inventor.

flitorne y.

Patented Sept. 14,1926.

rmn'r Lorznamor IBEBLIN-NEU-COLOGNE, enmrm.

CALCULATING DEVICE'IN THE FORM OF A SLIDE RULE.

application filed June 27, 1924, Serial No. 722,746, and in Germany July1, 1923.

My invention relates to a calculating de vice in the form of aslide-rule of handy shape and with a large unit of measure. This imroved calculating-device or sliderule is i] ustrated by way of examplein the accompanying drawings in which Figure 1 is a plan thereof; Figure2 is a section in line A-B of Fig. 1, seen from the right to the left;Figure 3 is a plan of a device for the simplied adjustin of a rotarybody which forms a part 0 the slide-rule to the result of thecalculation; Figure 4 is a section in the line GH of Fig. 3, seen fromthe left to the ri ht; Figures 5, (3, 7, 8 show a modification 0 thedevice shown in Figs. 3 and 4, Fig. 8 being a section in line EF of Fig.6, seen from above; Figures 9 and 10 are details of an adjusting andtransferdevice which is illustrated in Figure 11 in plan, a part of thecovering plate of the device being broken off at the upper left handcorner of the figure; and Figure 12 is a section in line C-D of Fig. 11,seen from the left to the right.

In a casing 1 is arranged a regular prism 2 of hexagonal cross-section,showing on its six surfaces the part-pieces of the logarithmicnumerical scale or graduation with the logarithmic unit '50 cm. Theprism 2 extends *in the longitudinal direction of the casing of thedevice or rule, and the ends of the axle of the prism lie in guide-waysrovided at the sides of the casing where t ey cooperate with springs 3and 4 in order to facilitate the step-wise rotation of the prism and tocause it to contact smoothly at its end with the covering-plate of thecasin The prism can be turned by means of a nob 5, but in connectionwith the lead-numbers mentioned later on it may be rotated nearlycompletely mechanically by means of cogwheels and an endless steel-band,as will be more full described hereinafter.

The prism which projects at its righthand end beyond the side-wall ofthe casing carries a counting-disk 6 which is also hexagonal and showsthe numerals 05. It is pressed against the knob 5 by means'of acompression spring 7 and engages it with a plurality of projections sothat it is turned together with the knob 5, but can'be turned alsoindependently thereof after having been shifted to the left so as to beuncoupled from the knob and to compress the spring 7 Parallelly to theprism 2 extends the scaleor graduation-chamber in which tion position.

superposed slides 8 9 10 can be shifted in guide-ways 11 .12 13. Eachslide is provided with a scale or graduation at both rims. The upperslide 8 is shown'in its computa- Above the three slides and the prism isarranged a slide 14 which 0on sist of glass and is provided on itsbottom slide with a line (not shown).

In this way slide-rules of, for instance, a logarithmic unit-of '50 cm.(length 53 cm., width 4.3- cm., height 1.3 cm.) can be reduced to alength of from 11 to 1115 cm., a width of 5.2 cm., and a height of 1.2cm.

In the constructional form shown by way of example the slide 8 isprovided at its front with the logarithmic scaleof the numbers and atits rear with the scale of the reci rocal numbers (inverse scale orgraduation); the slide 9 is provided at its front with the squarenumbers and at its rear with the cubic numbers; and the slide 10 isprovided at its front with the sine scale or graduation and at its .rearwith the tangent scale or graduation; each scale or graduation consistsof six equal parts. It is possible to add in a convenient manner otherscales or graduations, and if, as occurs oftentimes, transfers from onescale or graduation to another scale or graduation take place theslide-rule may have double the length.

The'manner of use of this slide-rule is practically the same as with anundivided slide-rule; anyhow, a' few particular points must be observed,viz:

The part-pieces of the scales or graduations show on the lefthand sidethe leading numbers from 0 to 5, and on the right-.

hand side the lead-numbers from 1 to 6, partly in colored fields. Thelead-numbers on the left side are valid for adjustments on the left, andthe leadnumbers on the right side are valid for adjustments on theright.

Example I 1.5 X 4.

The rotary prism is turned until the partgraduation showing the quantityor magnitude 1.5 appears. Then this quantity or magnitude is adjusted bymeans of the cursor and thereafter the slide designated with 1 isadjusted in the same manner as in an undivided slide-rule. Now he cursoris adjusted on the number 4 of the slide and the prism is turned furtherfor 3 graduations in conformity with the lead-number 3 of the left side.In order to obviate mistakes, the

counting-disk 6 is used for that adjustment.

In the same manner such calculations as, for instance, 1.5 X 5, or 1.5 X6, and the like, are carried through.

Example II: 6.5 X 5.

The cursor is moved to the number 6.5 of the rotatory prism; the slidebearing the number is adjusted on the line of the cursor. The prism isturned rearwards for 4 graduations (division) according to thelead-number 5 on the left. Reading-elf under the mark 1 left on therotatory prism shows the result 1.3. a

It does not seem necessary to give further examples. But it is necessaryto call attention to the feature that when square numbers or cubicnumbers, as well as square roots and cubic roots, are read oil, and alsowhen sine quantities or values or tangent quantities or values are readoil, the lead numbers of the art graduations of the slide and of theprisms must agree with each other.

Great accuracy can be obtained when the slide-rule is manufactured ot' ametal, and its applicability can be rendered multifarious by theprovision of a large number ofslides. The manipulation can be si1n'-plified very much by the provision of mechanical turning devicesoperatedin connection with the lead numbers.

I now proceed to describe the modified form illustrated in Figures 11and 12, of which details are shown in Figures 9 and 10. This device isan adjusting and transfer-device, combined with an automatic device forascertaining the number of the digits. In the example shown the deviceis intended for a comparatively largeunit of measure which forms a wholeor total.

The casing is divided into three parts 15 16 17 at the righthand lowercorner is provided a small by-chamber 18 in which are housed the meansfor ascertaining the number of the digits; the cover of the cas- 111g isbroken away over this by-chamber, as well as at the upper left-handcorner of the main-casing.

In the casing-part 15 is located the rotatory body or hexagonal prism19, on the six surfaces of which the part-scales or graduations of alogarithmic scale or graduation are provided in their proper succession.The body or prism 19 is also in this case, as in Figs. 1 and 2,supported elastically (at 20 and 21) for the purpose of facilitating,the adjustment of its individual surfaces, and is connected at its .endswith bevel-wheels 22 and 23. In the cover of the casing, above theprism, is a longitudinal sight slot 19', through which that prism sidewhich is the uppermost at the time being can be seen. The casing part 16contains in its upper part the calculation plate or slide 25 which isshiftable in guideways 26 and 27 and bears the part-scales orgraduations of a logarithmic scale or graduation like that of the prism19. Below the slide 25 is located a plate 28 hearing on its ends thelead-numbers or the limit numbers; a part of the plate is shown in Fig.9. Below the plate 28 are arranged, near the lateral ends of the casing,two rollers 29 and 30 which lie crosswise in the easing and areconnected with bevel-wheels 31 and 32 meshing with bevel-wheels 55 and56 secured to a shaft 54 to which I shall revert later on.

Parallelly to the rollers or cylinders 29 and 30 are arranged shafts 33and 34 of square section, and on them are adjusting wheels 35 and 36which can be shifted along said shafts by means of adjusting knobs 37and 38, each of which is connected with a short horizontal fork-likemember holding the appertaining adjusting-wheel (35, or 36 respectively)between its prongs. Each fork-like member is provided with a hand 40(Fig. 9), with the aid of which the appertaining adjusting-wheel (35, or36 respectively) is adjusted to the scale or graduation required. Thesquare shafts 33 and- 34 project into the casing part containim therotatory prism and are here provided with bevel-wheels 41 and 42 meshingwith bevelwheels 22 and 23 connected with said prism.

Ilighthand from the cylinder 29 is located a cog-wheel 43 (Fig. 11);another such wheel is located lefthand from the cylinder 30; it iscovered by the cover of the casing and not visible from this reason.Both these cog-wheels mesh with a rack provided at the bottom-surface ofthe slide 25 and serving for, the fine-adjustment thereof. Eachcog-wheel 43 is secured to a shaft 46 which extends outwards, near thebevel-wheels 55 and 56, and is there provided with a small disk 44, or45 respectively, serving as handle for turning the respective shaft(46). Below the cylinders or rollers 29 is a space or chamber 47 (Fig.12) in which one or more-other, additional, calculation slides may bestored.

On the top of the casing is a cursor having one or more hair-lines 51,and guideways 48 and 49 are provided on which the cursor may be shiftedlaterally in either direction.

The casing-part 17 contains a driving mechanism consisting of a crank52, a bevelwheel 53, and a beve wheel 57 which is made integral with thebevel-wheel 56 already mentioned. The crank 52 can be turned inclock-wise direction (which means: in the additive sense), as well as inthe reverse direction (which means: in the subtractive sense). Thefirst-mentioned direction is used for multiplications, the other fordivisions, especially with uniform scales or graduations. Means may beint I automatically when a rotation has provided to restrict twodirections of rotation of the crank to one in order to prevent mistakes;besides, in order to cause that only complete revolutions can be madewith the crank (52), there is provided at its rear surface a pin 58(Fig/11), combined with a spring which can engage a notch n'ovided in asmall stationary disk 59. Tile spring can be disengaged from said notchby means of a small knob located on the upper side of the crank, thearrangement bein such, that this disengagement must ta 'e place beforethe crank can be turned, and the rotation is stopped een completed, thespring-end entering then said notch.

Supposing, the calculation 1836x2165 must be made; then the cursor 50 isadjusted to the number 1836 of the rotary prism and the slide is soshifted that its first line coincides with the hair-line of the cursorand is, therefore situated over that adjusted number. Now the cursor isshifted again so that its hair-line is located on the number 2165 of theslide, and then the adjusting Wheel is shifted on its square shaft 33 bymeans of the knob 37, to that scale or raduation of the slide wherethere stands t e number 2165, which is the scale or graduation to whichpoints the hand in Fig. 9. When thereafter the crank 52 is turned onetime in the additive sense, the result 39.75 can be read off the rotaryprism, the number of the digits being, of course, considered. By therotation of the crank 52 the rollers or cylinders 29 and 20 have beenrotated, but

the latter roller or cylinder has not become active as the appertainingadjusting wheel 36 was in its position of rest. The adjusting-wheel 35,however, is rotated by the transmitting members 53 57 54 55 31 29, and;the rotation of the shaft 33 is transmitted further by the bevel-wheels41 and 42 to the prism 19 which latter is rotated corresponding to theadjustment previously made. i 1

Electric means may be provided for turning the transmission membersmentioned (53 29), and known means maybe used to cause the resetting ofthe adjusting wheel to its initial position,

Of the device for the automat c ascertainment of the number oi thedigits (is in Fig. 11) only an example is shown in Fig. 11. A

/ side-view of this device, partly, in section, is

shown in Fig. 10 and drawn to an enlarged scale. The lop partof thecasing 60 (Fig. 10) is omitted in Fig. 11. In the top-part is the sightslot or hole 61 (Fig. 10) through which the top-number of the disk 64 atthe time bein can be seen. This disk is connected wit 1 a cog-wheel 63which is engaged atevery revolution of the cog-wheel 23 (Fig. 11 by apin or other pro ection provided at a disk 62 connected with thiscog-wheel. The cog-wheel-63 is checked in every position by a sprin 89Fig. 10) secured to the casing'60. Tie w eel 62 rigidly mounted on theshaft of the rotar body 19 and provided in thisncase wit only one toothor projection engages, after it has made a complete revolution, with thetoothed wheel 63 which has, in the present case, ten teeth, for example,and is mounted on a shaft and rigidly connectedto a toothed wheel 64.The blade spring 89 engages a gap between two teeth of the wheel 63 andcompels it to advance only by one tooth or one number. The casing 60 isattached to'the main casing by means of a lug (Fig. 11) provided at thefront-wall of the main casing and engaing a sleeve-like member 66forming a part of the casing 60, the members 65 and 66 I being normallyheld. in engagement with each other by a spring (not shown). At the disk64 is provided a hollow branch-like projection 67 which is intended toserve as a handle and with the aid of which the members 65 and 66 can bedisengaged so as to enable the operator to remove the casing 60 with theparts it carries from the main casing. Said member 67 may, however, alsobe used for turning, i. e., adjusting, the disk 64 to another digit ornumber.

Examples:

H (1) 2.4-:0.062; E=+ l; S 2 +2; re-

sult 38.7.

2 fi X00234; 11: S: 1;

sult 0.0833.

(3) 2 E: 1; S24; result 1024.

'ILhecounting-disk may be replaced by a The apparatus may be employedalso for making additions and subtractions, if, for instance, the slide25 or another slide suited as equivalent for it, and on avsuitablydevised and ar'rangedrotatory body, such as a prism or the like, scalesof graduations with uniform division, are provided. With a unit ofmeasure of 5 m. for the scales or graduations it is possible to reckonaccurate ly, without any estimation, up to 99999. The above-describeddevice for ascertaining the number of the digits is now used for statingthe ten thousands; it is preferably provided at the. left side of theapparatus. The range of the calculations can be extended to more digitsby enlarging the apparatus similarly to the manner known withcalculating machines. The device for ascertaining the number of thedigits may be used in a corresponding manner also with calculatingrollers and other calculating devices.

The apparatus is a combination of a calculating machine with aslide-rule and is distinguished by its affording the advantages of bothmachines and said rules. Apart from the great speed with which theresult 73 on the left side and 69 and 74 on the '4 for the sake ofdistinctness.

right side, and of twoendless bands and 71 having each a row orplurality of holes 72. The distance between the holes of each bandagrees with the distance between the scales or graduations, and saidholes are engaged by pins provided around the circumference of thewheels 7 2-) and 74. These wheels are afiixed to the ends of the axle ofthe rotatory body 2, and the entire movable system (70 71 68 73 puttinga pin into any one of the holes 72 having a suitable position at thetime being, and by moving the respective band in one or the otherdirection. 7 5 and 76 are abutments. In the case of a multiplication thepin is inserted into that hole 72 which is located at the side of thescale or graduation concerned, and is moved in the direction to theabutment or 7(3) pertaining to the respective side of the device. In thecase of a division the pin is inserted into one or the other band at theappertaining abutment and is then moved, with the" band, to the scale'orgraduation concerned, that is to that scale or graduation which bearsthe number concerned. Whether the lefthand band etc. or the righthandband etc. is to be used is determined automatically by the numberconcerned,-as the length of the slide located above the scales orgraduations is such that the two'bands are never accessible at a time,always only one thereof, either the left or the right. But both bandsare covered when the slide is in its position of rest in which thecasing of the device is closed. The slide is omitted in Figs. 3 and Theplate 28 visible in Figs. 3 and 4 is an equivalent to the stationaryplate 28 in Figs. 11 and 12, and it bears also in this case (Figs. 3 and4:) the lead-number and the limit-numbers at its lefthand and right-handrim.

Example: 2.75 4.4:12.1.

The index line on the right side is adjusted to the quantity ormagnitude 2.75 of the respective scale or graduation of the rotatoryprism, and the cursor is so adjusted that its line coincides with thequantity or magnitude 4.4 of the slide. T henthe pin is put into thathole of the band 71 which lies at the side of the end-number 4.64,whereafter the band is moved by the pin until this latter contactswitlrgthe abutment '76. The result 12.1 can be read off at once on thatscale or graduation; ofithe body 2 which is on the top at thetirtijbeing.

(i9 74L) is actuated by Figs. 5.-8, there are, the endless bands, (70,laced by racks 80. It

Referring now to in this modification, 71, Figs. 3 and 4) re must beunderstood t kind shown in these figures. are combiner with the slideand plate etc. as in Figs. 3 and 4, one device being on the left, theother on the right of said other member of the apparatus. There is,therefore, of course, also a rotatory body such as 2, Fig. 3 and each ofthe projecting ends of the axle of this carries a sleeve 77 which isrotated with the axle and is shiftable on the respective axle-end. Eachof the two sleeves is provided with two cog-wheels 78 and 79 (Figs. 6and 8). There is also in this case an abutment (81, Figs. 5 and 7) forthe pin by which one or the' other rack 80 is shifted in the directionto the respective abutment; Each rack 80 is connected with two racks 82and 83 (Fig. 6) which mesh with the before-mentioned cog-wheels 78 and79 and are connected with tension springs 8d and 85 by which they arewithdrawn into their former position. But as the sleeve 77 with thecog-wheels 78 and 79 is shiftable on the appertaining axle-end, asalready described, and as the distance between these wheels is less thanthe distance between the racks 82 and 83, either one or the other ofthese cog-wheels meshes with the rack pertaining to it, the arrangementbeing such that one of the racks in question (82 83) serves for turningthe body 2 in one direction and the other serves for turning it in theother direction, but the movement, of the rack moving in the directionto the body 2 is effected by the pin or the like (Fig. 5) and themovement in the reverse is effected by the springs 84. and 85. The racks82 83 and the cog-wheels 78 and 79 are provided with ratchet-teeth, andthe teeth of the rack 82 and the wheel 78 are directed reversely tothose of the rack 83 and the wheel 79, and an elastic pawl 86 (Fig. 5)is provided ,which co-operates with the wheel 78 and prevents it frombeing rotated in the wrong direction. A similar pawl or, may be, aspring is provided also for the wheel 79.

The sleeve 77 with the two wheels in question is shifted in one or theother direction by means of the members 87 and 88 in Fig. 8. If theparts are shifted to the right, the driving gear is adjusted for thecrforming of divisions, and if they are shi ed to the left, the drivinggear is adjusted for making multiplications. In both cases the gear isoperated by shifting-the rack 80 in the same direction, viz, in thedirection to the abutment 81 where the path of the pin ends. In allother respects the manner in which the calculation is carried through ispractically the same as has been described with reference to the otherforms shown;

iat two devices of the adapted to be moved transverely over said plateand said slot; and means supporting elastically the said rotary body atthe ends of its axle, substantially as described;

2. A calculating device, comprising, in combination, an oblon casing; arotary body arranged lon itn inally below an inspection slot provi ed inthe oblong casing, and bearing a plurality of scales also ext-en inlongitudinally; a longitudinally shiftab. e plate arranged in saidcasing parallel to said rotary body and bearingal'so a plurality ofscales extending longitudinall thereon; bevel-wheels meshing with saiwheels; shafts of angular section connected.

with the other bevel-wheels; friction-disks arranged shiftably on saidshafts, one on either thereof; members shifted together with thesewheels; hands connected with these members, one with. either thereof;and being arranged to point to the ends of g the scales on the plate;friction-rollers ar- -ranged to contact with. said friction-wheels andlocated below the said plate; and means for rotating said rollerssimultaneously and uniformly substantially as set forth.

' 8. A calculating device, comprising, in

combintion,. an oblong casing; a rotary body arranged lon 'itudinallyelow an inspection slot provi ed in the oblong casing,

and bearing a plurality of scales also exten in longitudinally; alongitudinally shiftab e plate arranged in said casing parallel to sa1drotary body and bearing also a plurality of scales extendinglongitudinally thereon; and a device adapted to ascertain automaticallythe number of the digit, as set forth.

4. A -calculating device, comprising, in

body arranged longitu inally below an in- 50. combination, an' obloncasing; a rotary spcction'slot provided in the oblong casing, I

and bearing a plurality of-scales also exten in longitudinally; alongitudinallyshift ab e plate arranged in said casing parallel to saidrotary body and bearing also a plurality. of scales extendinglongitudinally thereon; a device adapted to ascertain automat-ically thenumber of the digits, and com- "prising a disk connected rigidly withthe said prismatic body; a projection on theieircumference thereof;'acog-wheel arranged in the plane of said disk and adapted to be turned ysaid projection; a spring arranged partly. to hold this cog-wheel 1nproper-position relatively to said disk; another disk connected firmlywith the cog-wheel and hearing on its circumference the numbers of thedigits; a casing enclosing this, device and having a si t-hole locatedover the digit-number disi' forth.

In testimony whereof I aflix my signature.

DR. PHIL'IPPLOTZBEY'EB. 1

, substantially as set,

